(1) Field of the Invention
The present invention relates to a power supply device where a wiring harness is foldably arranged along a harness winding section within a protector. The power supply device can be employed for example in a sliding door of a vehicle.
(2) Description of the Related Art
An exemplary conventional power supply device is shown in FIGS. 11 and 12. For example, the conventional power supply device is disclosed in Japanese Publication of Patent Application No. 2001-354085. In detail, refer to FIGS. 4, 7, and 13 of the Japanese publication.
In FIGS. 11 and 12, the power supply device 50 is positioned on the sliding door 41 of a vehicle, and is shown to include a protector 42 formed of synthetic resin material and configured to receive a wiring harness 43, and a flat spring 44 capable of upwardly energizing the wiring harness 43 within the protector 42.
The protector 42 is comprised of a protective base (also designated as a reference numeral 42) and a protective cover (now shown). The protective cover and the protective base respectively have an opposing substrate 51 and a peripheral wall 52. The protective cover is engaged with the protective base, which is secured to the panel of the sliding door 41 by means of a bolt 56, a crimping means and so on. A circular harness winding section 54 for controlling the radius of curvature of the wiring harness 43 and the flat spring 44 are unitarily formed on the inner surface of the substrate 51.
The lower end of the flat spring 44 is secured to the wiring harness 43 as well as a harness fixing section 55 disposed in the protector 42. A cap member formed of synthetic resin and positioned in the front end of the flat spring 44 supports the wiring harness 43 in a stable manner.
During the wiring harness 43, there are provided a plurality of insulated electrical wires 43a, which are covered with a corrugate tube 43b formed of synthetic resin. In this configuration, the front end of the corrugate tube 43b is secured to the harness fixing section 55 of the protector 42 by means of a fixing member such as tapes. The corrugate tube 43b has a good flexibility, which is because it has alternate circumferential convex and concave portions in its longitudinal direction.
The electrical wires 43a of the wiring harness 43 extend through the front portion of the protector 42, and then are connected to the accessory of the sliding door side. The corrugate tube 43b of the wiring harness 43 extends through an lower elongated opening 45 of the protector 42, then a space 46 (refer to FIG. 7), and then a fixture 53 of the wiring harness 43 side (also designated as a harness fixing section), which is positioned in a vehicle body 47, while holding its all freedom of movement. Finally, the corrugated tube 43b is connected to the wiring harness (now shown) of the vehicle body side by means of a connector. The protector 42 is covered with a door trim piece (now shown) formed with synthetic resin, and therefore is invisible. The wiring harness 43 extends through the opening of the door trim piece, and then the vehicle body side.
FIGS. 11 and 12 respectively illustrate the sliding door 41 in its fully closed position and fully open position. In its fully closed position, the wiring harness 43 is pulled in a rearward direction while being supported by the harness fixture 53 of the wiring harness 43. On the other hand, in its fully open position, the wiring harness 43 is pulled in a forward direction, and therefore is bent along the circumferential plane of the harness winding section 54, allowing for controlling the minimum radius of curvature of both the flat spring 44 and the wiring harness 43. As a result, both the flat spring 44 and the wiring harness 43 are prevented from undergoing excessive plastic deformation.
Under the condition where the sliding door 41 is partially open, while the wiring harness 43 is inclined to unroll in a downward direction, it is energized in an upward direction by use of the flat spring 44 and therefore the extra length of the wiring harness (i.e. the remaining length of the wiring harness) can be received. As a result, the extra length of the wiring harness 43 can prevented from being jammed. Immediately after opening, the sliding door 41 moves along a guide rail (now shown) while departing from the vehicle body 47 side.
Meanwhile, in the case of using afore-mentioned device for supplying electric power to a vehicle sliding door, in particular, a sliding door for a light car or a small sized car, due to its small stroke needed for its opening or closing, the harness winding section 54 should have a relatively large diameter. This is for suppressing the bending or folding of both the wiring harness 43 and the flat spring 44. In addition, the protector 42 has a tendency to gain more height in order to fully receive the extra length of the wiring harness 43. Moreover, the harness winding section 54 requires a relatively large amount of space within the protector 42, thereby increasing the protector 42 in size. Also, a relatively expensive flat spring and a cap member positioned in the front end of the flat spring are required, thereby increasing the prepare cost of the power supply device.
To solve the afore-mentioned drawbacks, the present invention is intended to provide a power supply device capable of reducing the protector size, the number of parts to be used therein, and the prepare cost thereof.